14 BOLT 6 LUG VS. 10 BOLT

i have a 98 z71 with ten bolt 3.73 and lockright locker. the truck is sitting on 35s right now but will soon be on 38.5s, i was wondering if 4.56 gears would do the trick and whether it would be better to go with a 14 bolt s6lug to replace the ten bolt or will the ten hold up to the tires. the truck is pretty hevily modded and is pushin roughly 4-500 horses is there anyone that can help me  

First, a 4.56 is not enough for 38's (neither is a 10 bolt). Next a 14 bolt 9.5 semi floater with 6 lugs hubs can handle it, No need for a 14 bolt 10.5. Last, people tend to overrate their engines and I would love to see a lot of them on dyno's. Unless you are running a radical cam with a very ruff idle and a tuned intake and a 6500 RPM or better power peak with high compression and high octane fuel in a SB, you are no were near 500 hp and likely not even at 400 HP. Also, actual axle shaft torque determines point of axle failure, not HP. You can break a axle with 50 HP and big tires with right gears and traction.  

I'd wanna run the 9.5 with 5.38 gears there...and a 1ton front diff.  
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see me at robsoffroad.com

the GM semi float axles are CRAP! if you are gonna replace the axle go with a D60 or higher or the 14Bolt FF (10.5 r/g)

even with a stronger axle, that IFS is gonna fall apart when yer on the freeway. it is no where NEAR rated for a tire that tall and wide. 35X12.5 max on 1/2 ton IFS

id say a 5.13 would do for the 39s. and if you stick with the 35s, go with a 4.56 before your tranny and axle snap like a twig.

you need a SAS with one ton axles to run those tires, safely. it might look cool until the spindle breaks and you kill someone.  
VirginiaK5

There is nothing wrong with a GM 14 bolt 9.5 semi floater and it is often overlooked. It is about the equal of a D60 and well above a 10 bolt in axle and housing strength. All 9.5 have a rated load capacity of about 6000 lbs too and the 1500HD (which is a 8600GVW 2500 in disguise)has used that axle since they came out with that model and still does. GM used that axle for about as many years as 10.5 and it say a lot of use in 3/4 ton truck and 1 ton vans in years past. The beauty of that axle is that it can be had in 6 and 8 lug flavors and a axle shaft chance is all that is needed to convert form one to other. It also weighs about 85 lbs less than 10.5 too because it lack heavy full floating hubs. It is strange to hear you recommend a D60 and not a 9.5 when a 9.5 is in same league as D60. Also while there has been some D60's in some 1/2 ton vehicles with LD housings and reduced load capacity, the 9.5 is only made one way in a 3 ton rated capacity housing. Another nice thing about 9.5 here is that carrier has more aftermarket posi/locker options because the straddle mount pinion limits carrier design and size on pinion side of ring gear while 9.5 does not.  This is not to say 10.5 is a bad axle but rather it is not needed over a 9.5 for a upgrade for a 1/2 ton 10 bolt 99% of the time but many seem to think it is.  

the semi 14bolt has alot of problems around here, i.e. axle shafts coming out.

yes it is ALOT better then a 10 or a 12, and if you lucky to get a 5 or 6 lug one, its a great upgrade. but not for 39s, better then a 10, but not the best.

conflict of opinion here haha  
VirginiaK5

I would like to find one of them 14 bolt axles to go under my truck. but i guess ill wait on the money to find one  

lol, thats from improper servicing, not the cause it's a semi floater, I've busted more axles and spiders in full floaters than the semi. it's no fun fixing the threads either when the nuts back off and the axles come out of the 10.5 just as frequently. the full is capable of heavier loads because of the bearings, although the semi has much larger shafts and tubes, due to the load is carried by the shaft, they are stonger than a d60 by far especially if we get into the d60 semi floater, the 14 bolt 9.5 axels are a upgrade for that one also

the 6 lugs aren't hard to find either, every light duty 2500 truck and burb has one from 88 on.

on the gear note...the 5:13's will leave a auto tranny searching for gears and riding the stall at the slightest inclines with the 38.5's running under 60mph (1880rpm's @ 60mph)  
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see me at robsoffroad.com

I would say that 5.13's are not perfect for 38's with a OD tranny but they are a whole lot better than much taller gears. Yukon makes 5.38 gears for 9.5. Up until a few years ago, 4.88 was about the limit for 9.5 as nobody really made anything deeper. Also, if I was getting to the point that I was breaking properly built 9.5's, I would likely skip 10.5 and go to GM/AAM 11.5 used in 2001 and later GM trucks with 8.1's and Dmaxs as it is lot stronger than a 10.5 and I would place it above a D80 too.  

im just a fan of FF over SF. the 14SF is a great semi, maybe the best. i just think if yer gonna go throught the money and trouble, go big.  
VirginiaK5

My view has long been the a extra weight is never a asset off road and more axle than you need is extra weight and in this case about 85 lbs and if you are worried somewhat about fuel cost, a 9.5 SF uses less fuel than a 10.5 FF because it has only two pinion bearing and low drag roller bearings the axles "float" on vs 10.5. This adds up to less power loss.  

i will be towing with it as well, and its almost finished haha.

i am gonna go with a D44 or 10 bolt 8lug up front though.  
VirginiaK5

ive got corp 10's on my 88 burb w/ superior evolution axles front and rear(not installed yet). do you guys think they will hold w/ 33's or 35's? I hope so they were about 6 bill per axle and i still need gears. shoul i have gone w 3/4 ton axles instead. i was thinking that at least i knew all was new. plus they say if you break the axles they will send you new ones. what do you think?  
Where's the time to work on MY stuff?

i woulda gone with 3/4, but a beefed up 10bolt can handle a 35 fine.

35s are the max tire for a 10 bolt, and with the added weight, the beefing up and hte proper gear ration will help.

rec a 4.88 from Yukon, Richmond, or Spicer Dana.  
VirginiaK5

NoTime:
ive got corp 10's on my 88 burb w/ superior evolution axles front and rear(not installed yet). do you guys think they will hold w/ 33's or 35's? I hope so they were about 6 bill per axle and i still need gears. shoul i have gone w 3/4 ton axles instead. i was thinking that at least i knew all was new. plus they say if you break the axles they will send you new ones. what do you think?

Sell/return axles and get a 14 bolt 9.5. You can get a nice 9.5 and even add gear and a posi for less than 1200 AND have a much stronger rear end. I have seen 10 bolt pigs shell out with 35's working hard when axles did fine. You kinda wasted your money sorry to say...